Tuesday, 13 January 2009: 11:00 AM
Climate and urban form effects on the water and energy budgets in a residential area of Salt Lake City, Utah
Room 124B (Phoenix Convention Center)
A residential catchment in the Salt Lake City metropolitan area has been instrumented to observe the water and energy budgets. The catchment has been physically characterized; precipitation, runoff, evapotranspiration, and soil moisture have been recorded continuously at high temporal resolution since the summer of 2007 (and before for some observations); water and energy use data have been and continue to be acquired from municipal officials; and numerical models of the energy and water budgets have been developed to simulate the interaction of urban form, climate, the energy budget, and water cycle processes. This paper reports primarily on the water budget observations and the results of the coupled water-energy budget model. Analysis of the continuous soil moisture observations produced a soil moisture decay function in non-irrigated landscapes. The soil moisture in non-irrigated catchments was found to respond to climate influences, but the soil moisture in irrigated landscapes did not display the same response to climate fluctuations (e.g., temperature). A preliminary comparison of soil moisture response to traditional landscape irrigation and drip irrigation associated with low water use vegetation landscapes suggested both produce nearly identical soil moisture levels, but the drip irrigation requires less water. Shading was found to have a minor impact on soil moisture response in irrigated landscapes. Lawn irrigation in the study catchment was found to contribute nearly 30% of the warm season discharges through the stormwater drainage system, with approximately 10% of the water applied being wasted. Conversion of the landscapes from turf grass to low water use vegetation would reduce water requirements from 15-40%, but the impact on the energy budget, other water cycle processes, and microclimate is uncertain. Results from a modeling study analyzing possible unforeseen impacts of landscape conversion on water use, ET, microclimate, and energy use will be included in the paper.